Conventionally, in a hybrid vehicle driving system including an engine, a generator and a motor, there is provided a power control unit (PCU) as a power controlling apparatus for controlling the generator and the electric motor.
The power control unit is made up of a generator inverter which is connected between a battery and the generator to convert an alternating current voltage into a direct current voltage, a motor inverter which is connected between the battery and the motor to convert a direct current voltage into an alternating current voltage or an alternating current voltage into a direct current voltage, and a control unit (ECU) for controlling the generator inverter and the motor inverter.
In the conventional hybrid vehicle driving system, a case where the generator and the motor are accommodated and the power control unit are mounted separately on a vehicle framework member. The power control unit is connected to the generator and the motor by way of a three-phase cable. This not only requires a mounting frame for the power control unit but also causes fears that noise is generated from the three-phase cable.
Then, as described in Patent Literatures 1, 2 it is proposed that the power control unit is mounted directly on the case. According to these hybrid vehicle drive systems, since the mounting frame for the power control unit and the three-phase cable are not required, there is provided such an advantage that not only a vehicle body weight and cost can be reduced but also the generation of noise can be suppressed.